Power Supplies for Use with Your
Switch
Each switch runs with two replaceable internal power supply modules that provide
all of the power needed for the switch to operate. You can remove one power
supply module without interrupting the switch's operation. Supported power supply
congurations include two 800 W AC power supply modules, two 800 W DC power
supply modules, or one 800 W AC and one 800 W DC power supply module. Power
supply modules have integrated cooling fans that operate independently of the switch
fans, and are available with front-to-back or back-to-front airow. The direction of the
airow in both power supply modules must be in the same direction, and must also be
the in same direction of the airow in the fan modules.
Power supplies are ordered separately for base model 7720-32C. Power supplies are
included with other models.
Precautions Specic to Power Supply Modules
Warning
Make sure that the power source circuits are properly grounded, then use the
power cord supplied with the device to connect it to the power source.
Warning
If the installation requires a different power cord than the one supplied with
the device, make sure you use a power cord displaying the mark of the safety
agency that denes the regulations for power cords in your country. The mark
is your assurance that the power cord can be used safely with the device.
Caution
Disassembling any part of the power supply and fan assembly voids the
warranty and regulatory certications. There are no user-serviceable parts
inside the power supply and fan assembly.
Caution
Ensure that the airow direction of the power supply unit matches that of
the installed fan tray. The power supplies and fan trays are clearly labeled with
either a green arrow with an "E", or an orange arrow with an "I."
18 Extreme 7720 Hardware Installation Guide